What Dose of CBD Did the Published Dog Studies Actually Use?

Across the five published canine osteoarthritis trials, the doses ranged from 0.25 mg/kg to 2.5 mg/kg of CBD, and most were given every 12 hours rather than once a day. The lowest starting dose was 0.25 mg/kg once daily; the highest was 2.5 mg/kg twice daily. Four of the five trials found a benefit. One found none. Here is every protocol, side by side, with the outcomes and the safety findings.

Nearly every hemp brand publishes a dosing calculator. Almost none publish the doses that were actually used in the peer-reviewed research, which makes it hard for an owner — or a veterinarian — to check a recommendation against the evidence. We have a reason to care about this: one of the five studies is ours. This page assembles all five, including the trial that failed and the liver-enzyme findings that brands tend to leave out.

The Five Trials at a Glance

These are the five studies that met inclusion criteria in the 2023 Frontiers in Veterinary Science systematic review of cannabidiol for canine osteoarthritis.

Note on the Verrico doses. That paper states its doses in milligrams per day, not per kilogram, and states once-daily administration. The systematic review tabulates the same arms as 0.5 mg/kg and 1.2 mg/kg every 12 hours — figures consistent with the mg/day totals divided by the study's 41 kg mean body weight, but the twice-daily frequency conflicts with the primary paper. We report the paper's own numbers above and flag the discrepancy rather than quietly picking one.

Study by Study

Gamble 2018 — Cornell University

Pharmacokinetics, Safety, and Clinical Efficacy of Cannabidiol Treatment in Osteoarthritic Dogs, Frontiers in Veterinary Science 2018;5:165.

The pharmacokinetic phase tested single doses of 2 mg/kg and 8 mg/kg. The clinical phase used 2 mg/kg every 12 hours for four weeks, in an industrial hemp extract reconstituted into an olive oil base. Outcomes were the Canine Brief Pain Inventory, the Hudson activity scale, veterinary lameness scoring and bloodwork.

The paper reports "a significant decrease in pain and increase in activity (p < 0.01) with CBD oil." It also reports an increase in alkaline phosphatase during CBD treatment (p < 0.01), seen in 9 of the 16 completing dogs. The 8 mg/kg figure belongs to the single-dose pharmacokinetic work only — it was not the efficacy dose, and it is sometimes misquoted as though it were.

Kogan, Hellyer & Downing 2020 — HempMy Pet with Colorado State University

The Use of Cannabidiol-Rich Hemp Oil Extract to Treat Canine Osteoarthritis-Related Pain: A Pilot Study, Journal of the American Holistic Veterinary Medical Association 2020;58:35–45.

This is our study, and its protocol is the outlier: it started far lower than the others and titrated upward. In the paper's words, qualified dogs "received a CBD oil product at a dose of 0.25 mg/kg delivered on food QD for 3 days and then morning and night (approximately every 12 hours)." Thereafter, "CBD dose escalations of 0.5 to 0.75 mg/kg approximately every 12 hours were prescribed at each reassessment until the patient's pain score on palpation was 0 to 1 on a scale of 10." Final doses landed between 0.3 and 4.12 mg/kg twice daily — a fourteen-fold spread between individual dogs.

Assessment was by systematic pain palpation with pain mapping on a 0–10 scale, every two weeks across 90 days, supervised by veterinary pain specialist Dr. Robin Downing. Thirty of the 32 completing dogs showed improved pain scores. Of the 23 dogs taking gabapentin at enrollment, 10 discontinued it and 11 of the remaining 13 reduced their dose.

The finding brands usually omit: the paper reports that "ALKP, but not ALT, increased significantly during the 90-day trial," with a mean increase of 130.8 ± 135 U/L. The authors recommend longer-term safety studies. It is our own paper and we would rather publish that than have you find it elsewhere. We cover what the wider literature says about this in our guide to hemp and CBD side effects in dogs.

Two limitations worth stating plainly: this was an open-label, single-arm pilot with no placebo group and a single assessor, and the authors acknowledge the bias that introduces. It was included in the systematic review but was not pooled into the numerical meta-analysis, because a single-arm design cannot be.

Verrico 2020

A randomized, double-blind, placebo-controlled study of daily cannabidiol for the treatment of canine osteoarthritis pain, Pain 2020;161(9):2191–2202.

Four parallel arms of five large dogs each (mean 41 kg): placebo in fractionated coconut oil, 20 mg/day of CBD isolate, 50 mg/day of CBD isolate, and 20 mg/day of a liposomal CBD formulation, all once daily for four weeks. Outcomes were the owner-completed Helsinki Chronic Pain Index and a veterinarian locomotion score.

The paper reports that "50-mg/day naked CBD or 20-mg/day liposomal CBD generated statistically significant reductions in pain symptomology" (p < 0.01). The 20 mg/day isolate arm did not reach significance — so within a single study, the same compound at the same frequency worked at one dose and not at a lower one. No significant changes were seen in bloodwork, including ALT and alkaline phosphatase, across the four weeks.

Brioschi 2020

Oral Transmucosal Cannabidiol Oil Formulation as Part of a Multimodal Analgesic Regimen, Animals 2020;10(9):1505.

The only trial in the set that did not give CBD by mouth in the usual sense. Owners administered it oral-transmucosally — into the buccal pouch with a needleless syringe — at 2 mg/kg every 12 hours for 12 weeks, added on top of an existing regimen of an anti-inflammatory, gabapentin and amitriptyline. The formulation was essentially an isolate in MCT oil, concentrated at 40, 100 or 200 mg/mL by patient weight, with under 0.01 mg/mL of other cannabinoids.

Pain Severity Score was significantly lower in the CBD group than the control group (p = 0.0002 at the first timepoint). Adverse effects: minimal ptyalism in 2 of 9 CBD dogs, and somnolence with mild ataxia in 3 of 21 dogs across both groups. No relevant changes in bloodwork in either group.

This is the trial to cite if someone asks whether the route matters. It is also an add-on design — it tells you what CBD contributed alongside conventional medication, not instead of it.

Mejia 2021 — Colorado State University

Evaluation of the Effect of Cannabidiol on Naturally Occurring Osteoarthritis-Associated Pain: A Pilot Study in Dogs, Journal of the American Animal Hospital Association 2021;57(2):81–90.

This trial found nothing. 2.5 mg/kg every 12 hours — the highest dose in the set — for six weeks per arm, in a randomised, double-blinded, placebo-controlled crossover design, with the most objective outcome measures of any of the five: force-platform gait analysis and accelerometer activity counts alongside the LOAD and CBPI questionnaires. The result, in the authors' words: "no differences noted between groups at any time point for any of the recorded outcome measures."

It also reported the highest rate of laboratory findings: elevated ALP, ALT and/or AST in 14 of the 23 dogs that received CBD, and vomiting in two.

A negative result at the highest dose, measured most objectively, is the single most important counterweight on this page. Any honest account of the canine evidence has to carry it.

What the Five Protocols Have in Common

• Twice daily, not once. Four of the five dosed every 12 hours. CBD clears a dog's system faster than most owners expect — see half-life.
• Weeks, not days. The shortest treatment period was four weeks; the longest was 12 weeks, and ours ran 90 days.
• A wide dose range with no consensus. 0.25 mg/kg to 2.5 mg/kg is a tenfold spread, and the highest dose produced the only null result. Nobody has established an optimal dose for dogs.
• Liver enzymes recur. Three of the five reported enzyme elevations — ours, Gamble's and Mejia's. Two reported none. Where values were given, they stayed within or near laboratory reference ranges, but the pattern is consistent enough that a baseline blood panel is a reasonable thing to ask your vet about.
• Formulations were not the same. Two used full-spectrum-type extracts, two used isolate, one added a liposomal arm and one was transmucosal. Doses are not directly comparable across different products.

What This Means for Your Dog — and What It Does Not

It does not mean you should pick a number off this page. These were supervised research protocols, several of them run alongside prescription medication, in dogs selected against inclusion criteria. What the range is genuinely useful for is context: it tells you whether a product's recommendation sits inside the studied territory or far outside it, and it gives your veterinarian something concrete to react to.

For practical serving guidance on our own products, our serving size guide works from your dog's weight, and every product page carries its own chart. The pattern our own trial supports is the one we recommend: start low, split it morning and night, and adjust slowly over weeks.

How to give it

All five studies gave CBD by mouth or into the cheek pouch, and four gave it twice daily roughly 12 hours apart. Giving it with food matters: cannabinoids are fat-soluble, and research in dogs has found meaningfully higher blood levels when CBD is given with a meal rather than on an empty stomach. Drop it onto food or give it straight after eating.

Sourcing and quality

None of the above is worth anything if the bottle does not contain what the label says. In an analysis of 29 over-the-counter veterinary hemp products published in Veterinary Medicine: Research and Reports, only 10 were within 10% of their label claim and 4 contained detectable heavy metals. Read the certificate of analysis — ours are published at lab results — and check the milligrams per millilitre so you can actually calculate a dose.

Cautions and when to see a vet

Give more than your dog needs and the common signs are mild drowsiness, wobbliness or loose stool, which pass on their own. Because CBD can affect how the liver processes some medications, talk with your veterinarian before starting if your dog takes anything else — and bring the COA. Ask about a baseline blood panel if your dog will be on it long term, which is what the enzyme findings above would support. See a vet promptly for any sudden change in appetite, vomiting that does not settle, jaundice, or lethargy that is out of character. Never stop or reduce a prescription on your own; every medication change in our trial was directed by the supervising veterinarian.

Frequently Asked Questions

What dose of CBD was used in the dog studies?
Between 0.25 mg/kg and 2.5 mg/kg, usually every 12 hours. Gamble 2018 and Brioschi 2020 used 2 mg/kg twice daily, Mejia 2021 used 2.5 mg/kg twice daily, our own trial started at 0.25 mg/kg and titrated to a final range of 0.3–4.12 mg/kg twice daily, and Verrico 2020 used 20–50 mg per day in large dogs.

Is there an agreed CBD dose for dogs?
No. The published doses span more than a tenfold range, the highest dose tested produced no measurable effect, and no regulatory body has established a dose for dogs. Anyone presenting a single authoritative number is going beyond the evidence.

Did any of the dog trials fail?
Yes. Mejia 2021 at Colorado State University used the highest dose in the set with the most objective measurements — force-platform gait analysis and accelerometers — and found no difference between CBD and placebo on any measure at any timepoint.

Do these studies show CBD raises liver enzymes in dogs?
Three of the five reported elevations: ours (ALKP up a mean 130.8 ± 135 U/L over 90 days), Gamble 2018 (ALP up in 9 of 16 dogs, p < 0.01), and Mejia 2021 (ALP, ALT and/or AST elevated in 14 of 23 dogs). Verrico 2020 and Brioschi 2020 reported no relevant changes. It is a real and repeated signal, which is why a baseline panel is worth discussing with your vet. We go through it study by study in our guide to hemp and CBD side effects in dogs.

Was 8 mg/kg a treatment dose in the Cornell study?
No — that figure is frequently misquoted. Gamble 2018 tested 2 mg/kg and 8 mg/kg as single doses in the pharmacokinetic phase only. The clinical trial used 2 mg/kg every 12 hours.

How long did the studies run?
Four weeks (Gamble, Verrico), six weeks per arm (Mejia), 12 weeks (Brioschi) and 90 days (ours). None of them measured a single dose for efficacy, which is why we say give it time.

Which studies were pooled in the meta-analysis?
Three: Gamble 2018, Brioschi 2020 and Mejia 2021, meta-analysed on the Canine Brief Pain Inventory. Ours was included in the systematic review but not pooled, because a single-arm design cannot be. Verrico 2020 was also not pooled, on formulation and outcome-instrument grounds. We describe our study as part of a systematic review, never as part of the meta-analysis.

Citations

• Gamble LJ, Boesch JM, Frye CW, Schwark WS, Mann S, Wolfe L, Brown H, Berthelsen ES, Wakshlag JJ. Pharmacokinetics, Safety, and Clinical Efficacy of Cannabidiol Treatment in Osteoarthritic Dogs. Front Vet Sci. 2018;5:165.
• Kogan L, Hellyer P, Downing R. The Use of Cannabidiol-Rich Hemp Oil Extract to Treat Canine Osteoarthritis-Related Pain: A Pilot Study. J Am Holist Vet Med Assoc. 2020;58:35–45.
• Verrico CD, Wesson S, Konduri V, et al. A randomized, double-blind, placebo-controlled study of daily cannabidiol for the treatment of canine osteoarthritis pain. Pain. 2020;161(9):2191–2202.
• Brioschi FA, Di Cesare F, Gioeni D, et al. Oral Transmucosal Cannabidiol Oil Formulation as Part of a Multimodal Analgesic Regimen. Animals. 2020;10(9):1505.
• Mejia S, Duerr FM, Griffenhagen G, McGrath S. Evaluation of the Effect of Cannabidiol on Naturally Occurring Osteoarthritis-Associated Pain: A Pilot Study in Dogs. J Am Anim Hosp Assoc. 2021;57(2):81–90.
• Efficacy and safety of cannabidiol for the treatment of canine osteoarthritis: a systematic review and meta-analysis. Front Vet Sci. 2023. doi:10.3389/fvets.2023.1248417

More on the trial we commissioned, including the researchers who ran it, is on our clinical trials page. If you want the products the studies used the closest analogue of, start with full-spectrum hemp oil for dogs.

Written by Marc Brannigan, Co-Founder & CEO of HempMy Pet. Marc founded HempMy Pet in 2016 and built it into a vertically integrated, seed-to-sale organic hemp company, and commissioned the company's two university clinical trials. Every figure on this page is taken from the published paper it is attributed to.
Last updated 12 September 2026.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. The doses described on this page are reports of published research protocols, not serving recommendations. Always consult your veterinarian before starting any new supplement, especially if your dog is taking medication or has a health condition.